A small group of chemicals is dangerous enough that communities must plan for their release before anything goes wrong. EPCRA Section 302 identifies these Extremely Hazardous Substances and sets a Threshold Planning Quantity for each. Knowing whether you store one of them above its threshold is the starting point for emergency planning, and it depends on tracking the listed substance rather than the product. That is where chemical management software earns its keep.
Why Section 302 Tracking Is Challenging
What Is an Extremely Hazardous Substance?
Extremely Hazardous Substances are chemicals listed in 40 CFR Part 355, Appendices A and B, under the Emergency Planning and Community Right-to-Know Act. The list contains roughly 350 substances selected because an acute release could cause serious harm to human health. Each substance is paired with a Threshold Planning Quantity, the on-site amount at which a facility becomes part of the local emergency planning process.
Threshold Planning Quantities Explained
A Threshold Planning Quantity is specific to each substance and is often far lower than the thresholds used for ordinary hazardous chemicals. Many EHSs have TPQs in the hundreds of pounds, and some are lower still. For certain solids, the regulation lists two TPQs: a lower value when the substance is in powder form or in solution, and a higher value for other physical forms. This is why an accurate inventory must capture not just the chemical, but its concentration and form.
Calculating On-Site EHS Quantities
The threshold applies to the amount of the listed substance present, not the total weight of the products that contain it. To find the on-site quantity of an EHS, multiply each product's concentration of the substance by the amount of that product stored, then add the results across all storage areas:
On-Site EHS = Sum of (Concentration x Product Quantity) Across Areas
Suppose a product is 5 percent of a given EHS, and you store 8,000 pounds of that product in one area:
5% x 8,000 lbs = 400 lbs of the listed substance in that area
If a second area holds another 2,000 pounds of the same product, that adds 100 pounds, for 500 pounds site-wide. Against a 500-pound TPQ, the facility has reached the threshold even though no single area did on its own. Summing across areas is exactly the step that manual tracking tends to miss.
How Ecesis Tracks Section 302 Compliance
Ecesis incorporates EPA's List of Lists, which includes the Section 302 EHS list and Threshold Planning Quantities. Working from your inventory, the software:
- Flags every chemical that appears on the Extremely Hazardous Substances list
- Calculates the on-site quantity of each EHS by applying product concentrations to stored amounts
- Aggregates those quantities across all storage areas to a facility-wide total
- Compares the total against the substance's Threshold Planning Quantity
- Lets you filter to on-site products only, so the planning list reflects current conditions
Ecesis Chemical Reporting Software
Chemical Management
Flag EHS chemicals and track concentrations across products.
Emergency Planning
Support LEPC coordination and facility response planning.
Compliance Obligations
Track Section 302 notifications and planning deadlines.
Incident Management
Record releases of listed substances and notifications made.
Inspections & Audits
Verify EHS storage quantities and conditions on-site.
Mobile App
Check EHS data and reportable quantities in the field.
